docs: def _split_standard_name(self, standard_name):
          '''
          Returns a tuple of the standard_name and standard_name modifier
  
          Nones are used to represent the absence of a modifier or standard_name
  
          :rtype: tuple
          :return: 2-tuple of standard_name and modifier as strings
          '''
  
          if isinstance(standard_name, basestring) and ' ' in standard_name:
              return standard_name.split(' ', 1)
          # if this isn't a string, then it doesn't make sense to split
          # -- treat value as standard name with no modifier
          else:
              return standard_name, None